Results

Thirty-three OLPs were identified as potential novel epitopes. A viral control epitope, RI10 (HIV-protease, previously described in HIV-1 B clade as -B*13 restricted) was found restricted by HLA-A*0203 in Thais. Interestingly, HLA-A*0203+ve patients with RI10 responders had a significantly lower VL than non-responders (p = 0.0167). This data may support the low VL from loss of viral fitness of RI10. Moreover, the patients exhibiting mutations in RI10 showed no ELISpot responses. Another known HLA-A*1101 epitope, AK11 (in Gag-p24) was also identified as a viral control epitope in this study. Of note, there was no significant mutation found in patients expressing A*1101. We also found a novel immunodominant epitope (29% response rate) restricted by HLA-Cw*0102: YI9 (in Gag-p24) which was associated with viral escape. Mutations at P2 (S278X), P4 (V280X) and P5 (S281G) impaired the Elispot responses, however the P2 anchor S278K mutation had the highest negative impact (p = 0.0002).

Conclusion

In HIV-1 CRF01_AE infected Thais we characterized three CD8 epitopes (RI10, AK11 and YI9) restricted by HLA-A*0203, -A*1101 and -Cw*0102, respectively. RI10 and AK11, but not YI9, were associated with lower VL and possible control of HIV. Further characterization of those possible novel epitopes is warranted.

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Corresponding author

Correspondence to
S Buranapraditkun.

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This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.